Hi there. Boy your son is really going through it eh? I am so sorry for all the trouble he is having.
By liquid diet are you referring to Exclusive Enteral Nutrition? (maybe not because he is having some oats and honey) Is he drinking his formula or using an NG Tube? For how long will he be on formula?
Both of my girls have done EEN to knock out inflammation and get then to remission. Generally speaking, enteral nutrition works best if exclusive although some centers are having success with 80/20. Typically, once food is introduced, unless there is a maintenance med, inflammation returns. Again, however, some centers are having success with up to a 50/50 plan.
My oldest went to an anti inflammatory diet after she did EEN and has done very, very well on it. She remained on Remicade but once we did the EEN and diet her health really took off so I have to assume more is at play than just Remicade. Even her GI can tell when she slacks on her diet. For her it is all bout clean foods. Limited dairy, very, very little meat (this info came from the Japan and Israel studies), little to no processed foods.
My younger daughter go to remission using EEN and we went to a similar diet but she couldn't get past the 80/20 without inflammation returning.
She is back on EEN and after this try we are going to use the IBD-AID diet that came out of UMass. The diet is similar to the SCD diet but allows more foods. This diet uses the principles or probiotic and prebiotic foods. It does not allow any grains, no lactose, no sugar, no corn and obviously no processed foods. It does allow lean meats but we will be limiting those to once a week based on the results of the Japan and Israel studies. She is 5-6 weeks EEN and then 80/20 for 8 weeks and we will take it from there. Our hope is to get her to 50/50 and that is where she will stay. She has tried Entocort and Methotrexate and neither has worked for her. For some reason, her doc doesn't want to move her to biologics and he won't use Imuran.
MLP uses the Crohn's exclusion diet. Very similar to the IBD-AID but there are a few differences.
There is a lot of research coming out of Israel and Japan on diet and it's benefits. The problem is the success of these diets is has only been linked so far to clinical resolution of symptoms. No studies on endoscopic results or even very reliable biomarker results yet.
I whole heartedly believe diet makes a difference. Whether or not it is enough to control disease alone is still to be seen but I say no harm in trying!
One key with reintro is to take it slowly and pick your foods wisely.
Check out the Parents section and the subsection on diet. Lots of info there.
Good Luck! Let us know how you get on.